No abstract

A mature ovarian teratoma is a common benign germ cell tumor of the ovary in women that rarely causes a malignant transformation. However, a malignant transformation can occur in the ectodermal, mesodermal, and endodermal tissues of the tumor. A squamous cell carcinoma is the most common and an adenocarcinoma is the second most common malignant tumor derived from a cystic teratoma. Due to the rarity of malignant transformations in mature teratomas and the lack of clinical data, the clinical pathological features, malignant transformation mechanism, therapeutic methods, and prognosis-relevant factors are unclear. Currently, there is no specific diagnostic method, and it is a difficult lesion to diagnose before performing surgery. In order to improve clinicians' understanding of a malignant-transformed mature teratoma and identification of malignant-transformed teratomas at early stages, we have reported a case of a mature teratoma with the malignant transformation of a sebaceous gland carcinoma in the Yiwu Central Hospital in Zhejiang, China on May 31, 2018. A review of the literature is also presented to summarize the clinical symptoms, pathogenesis, diagnosis, and treatment of malignant-transformed mature teratomas.